For purposes of enhancing the production of a hydrocarbon (oil or gas) from a hydrocarbon-bearing reservoir, a hydraulic fracture operation may be conducted to induce fractures in the reservoir rock. With hydraulic fracturing, a fracturing fluid is pumped downhole to create a downhole hydraulic pressure that causes a network of fractures to form in the reservoir rock. A fracture pack (proppant, for example) may be communicated downhole with the fracturing fluid for purposes of depositing the pack inside the fractures to hold the fractures open when the hydraulic pressure is released. To observe the progress, geometry and extent of an ongoing fracturing operation, hydraulic fracture monitoring (HFM) may be employed. With passive micro-seismic HFM, an array of geophones may be deployed on the surface, in a neighboring well or in the well to be fractured and used to map microseismic events, which are created by the fracturing process.